Graham said the measure, offered as an amendment to the annual appropriations bill for the Commerce and Justice Departments, was needed to head off what he said were plans by the Obama administration to send Khalid Sheikh Mohammed and others allegedly involved in the Sept. 11 plot to trials before civilian courts in the U.S.

“These people are not criminals. They’re warriors — and they need to be dealt with in a legal system that recognizes that,” Graham said. “Khalid Sheikh Mohammed, the mastermind of 9/11, did not rob a liquor store.”

“The attacks of 9/11 were not a crime. They were a war crime,” Sen. John McCain (R-Ariz.) said.

Some Democrats flatly disagreed, arguing that military trials could play into the Al Qaeda operatives’ claims that they are fighters in a holy war against America.

“They are criminals. They committed murder,” Sen. Jack Reed (D-R.I.) said. “These are not holy warriors. They are criminals.”

Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.) said it was bizarre to declare that the 9/11 suspects couldn’t be tried in federal court, but everyone else in the world could be, at least potentially.

“That’s Alice in Wonderland justice. It makes no sense,” Leahy said. “Are we going to tell the world [that] we’re not up to trying people who struck at us?... Our courts, our prisons are more than up to the task.”

The Obama administration vigorously opposed the amendment and insisted that officials retain the option to decide whether a civilian or military forum best suited for a particular case. Last week, Defense Secretary Robert Gates and Attorney General Eric Holder sent senators a letter warning that Graham’s proposal "would be unwise, and would set a dangerous precedent."

A White House spokesman had no comment Thursday evening on the amendment’s defeat.

Many Democrats complained that the legislation amounted to micromanagement of the executive branch by the Congress — something Republicans often warned against under President George W. Bush.